Insulating metallic surfaces or wires.



UNITED STATES PATENT OFFICE.

JOHN A. HEANY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE TETER-HEANY DEVELOPING COMPANY, OF PHILADELPHIA, PENNSYL- VANIA, AND CHARLESTON, EST VIRGINIA, A CORPORATION OF VEST VIRGINIA.

INSULATING METALLIC SURFACES OR WIRES.

SPECIFICATION forming part of Letters Patent No. 703,198, dated June 24, 1902.

Application filed November 9, 1901, Serial No. 81,729. (No specimens) T0 [0, whom it may concern:

Be it known that I, JOHN ALLEN HEANY, a citizen of the United States, residing at the city of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Insulating Metallic Surfaces or Wires, of which the following is a specification.

My invention has relation to the insulation of electric wires or other metallic surfaces by means of a compound containing asbestos.

Heretofore the use of asbestos as an insulating material has been limited by reason of the fact that it could not be applied to the metal in a thin pliable form and yet be made Waterproof,firepr0of, and adhesive under conditions of excessive heat applied through the metallic surface or extraneously applied to the asbestos covering. As is well known, asbestos is an absorbent of moisture and is not absolutely fireproof, because if exposed to a Bunsen flame the fiber of asbestos loses its flexibility and becomes exceedingly brittle by reason of the driving off of the water of crystallization. When so heated, a chemical change in the asbestos results in its deterioration as an insulating material, the asbestos being converted into oxide and the fiber made brittle.

The principal object of my present invention is to provide an insulation or covering for electric wires or metallic surface which shall be fireproof, waterproof, and sufficiently thin, pliable, and adhesive to permit the wire or surface to be bent into helices or coils without impairing the efficiency of the covering.

In carrying out my invention the metallic wire or'surface is first coated or covered with a paste or cement containing the following ingredients, to Wit: first composition, fishglue or gelatinous or albuminous substances combined with lime, either wholly or partly slaked; second solution, sulfate of ammonia, boracic acid, sulfate of soda, chlorid of am monia, chlorid of soda, and water. After either the first composition or the second solution has been applied to the metallic wire or surface the asbestos is first treated with the second solution containing the chemical salts, as above set forth, and is then dried, picked into flaky or fibrous form, and then twisted under pressure upon the coated and sticky wire or metallic surface. The asbes tos covering thus applied is then covered or coated with a paste or cement containing the first composition of lime with the albumiuous or gelatinous material mixed with the solution of chemical salts, as above set forth, and, if desired, is again pressed down upon the wire or metallic surface. 'lhe'coating or covering thus applied to the metallic wire orsurface will be found to be a perfect insulation, water and fire proof, thin, pliable, and flexible, and adhering to the wire or metal surface under extraordinary conditions of temperature.

If desired, and in some instances this is preferable, the wire or metallic surface before it is covered with either the first composition or the second solution, as in the first instance, may be treated or immersed in a bath of zinc chlorid, which chlorid is allowed to dry upon the wire or surface before the first composition, containing lime and albu minous orgelatinous substances combined with the solution of chemical salts, is applied to the wire. The zinc chlorid in this instance serves not only to clean the Wire or metal surface, but when the wire or surface is subjected to extreme heat after the insulation has been applied the chlorin is driven off, and metallic Zinc remaining will chemically combine with the metal surface and With certain of the ingredients of the paste or cement. The adhesion of the asbestos to the metal wire or surface is thus increased.

In divisions of the present application serially numbered 88,897, of January 8, 1902, and 88,972, of January 9, 1902, the method of preparing the asbestos as well as the method of applying the insulation to the metallic surfaces are claimed.

Having thus described the nature and objects of my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. As an improvement in insulating material adapted for application to a metallic sur face or wire, a paste of albuminous or gelatinous material and lime and dry and flaky asbestos impregnated with chemical salts, substantially as and for the purposes described.

2. As an improvement in insulating material adapted for application to a metallic surface er wire, a paste of albnminous or gelatinous material and lime, combined with dry and llaky asbestos impregnated with chemical salts and a covering of the paste mixed with chemical salts, substantially as and for the purposes described.

be As an improvement in insulating material adapted for application to a metallic surface or wire, a paste of albuminous or gelatinous material and lime combined with dry 

